Game Development Reference
We've already discussed the force due to gravity in earlier chapters, so we won't address
it again in this chapter except to say that the total of all lift forces must be greater than
or equal to the gravitational force if an aircraft is to maintain flight.
To address the other three forces acting on an aircraft, we'll refer to a simplified, generic
model of an airplane and use it as an illustrative example. There are far too many aircraft
types and configurations to treat them all in this short chapter. Moreover, the subject
of aerodynamics is too broad and complex. Therefore, the model that we'll look at will
be of a typical subsonic configuration, as shown in Figure 15-2 .
Figure 15-2. Model configuration
In this configuration the main lifting surfaces (the large wings) are located forward on
the aircraft, with relatively smaller lifting surfaces located toward the tail. This is the
basic arrangement of most aircraft in existence today.
We'll have to make some assumptions in order to make even this simplified model
manageable. Further, we'll rely on empirical data and formulas for the calculation of lift
and drag forces.
Before getting into lift, drag, and thrust, we need to go over some basic geometry and
terms to make sure we are speaking the same language. Familiarity with these terms